The present invention relates to a system for correcting a shift of the ignition timing occurring in an ignition device used with internal combustion engines.
In recent years ignition devices used with motor vehicles have been and are required to have increased output energy and have improved accuracy and stability of the ignition timing in view of the purification requirements of the exhausted gases from motor vehicles. Under these circumstances, ignition devices of the conventional contact breaker type are increasingly replaced by those of the fully transistorized type without contact breakers.
In these fully transistorized type of ignition devices, the ignition timing signal is provided by a contactless signal generator such as an electromagnetic coil generator, an integrated circuit Hall generator or the like, but such a generator is disposed within a mating distributor which is, in turn, usually driven by a crankshaft connected to an associated internal combustion engine through a timing belt or the like. Even in fully transistorized ignition devices, therefore, a shift of the ignition timing due to ageing change in the distributor driving system is increased with time. This shift of the ignition timing appears as a shift of the ignition timing developed during the idling of the engine and has greatly affected the output from the engines and the ingredients of the exhaust gases from the engines.
Therefore, the shift of the ignition timing is undesirable in view of measures to counter the exhaust gas emissions from internal combustion engines. Thus, it is desirable to correct a shift of the ignition timing of internal combustion engines by some measure. Furthermore, it is desirable to correct the ignition timing when knocking occurs in internal combustion engines for the purpose of stopping the knocking.